Scientists are turning their attention to thorium, a cleaner and cheaper
alternative to uranium.

Two years after the Fukushima disaster rocked the nuclear industry, the jury is still out in many countries on the role of atomic fuels.

Just two of Japan's 54 commercial nuclear plants are currently operational, while Germany has abandoned nuclear altogether. The price of uranium has also plummeted, making it unviable to get new mines off the ground.

But in the background, scientists are working on a cleaner, cheaper and safer alternative to uranium. It's even named after a god.

Thorium is more common in the Earth's crust than tin, mercury and silver - and three times more abundant that uranium. In fact, thorium, which is named after Thor, the Norse god of thunder, is so energy-dense that an individual can hold a lifetime's supply of electricity in the palm of their hand.

Around 14pc of the world's electricity is currently generated using nuclear power; in France, the figure is closer to 75pc. But with uncertainty over uranium prices, emissions targets to be met and a need to address post-Fukushima safety concerns, policymakers and the industry have been forced to think again.

There is also the issue of nuclear proliferation. In a traditional light-water reactor, plutonium-239 - a radioactive isotope that can be used to make weapons - is generated as a by-product of uranium-235/238 nuclear reactions. However, using thorium instead of uranium to kick-start nuclear fission produces less long-lived waste such as plutonium, reducing the security issues associated with nuclear plants.

Thorium is not a new discovery, and Britain led the way in the late 1960s and early 70s with tests in the Dragon Reactor in Winfrith, Dorset.

Thorium has huge energy potential but is in technical terms fertile, not fissile, meaning that it needs to be converted into uranium-233, another variant of the element, before it can be used to generate electricity. However, a lack of the vital spare neutrons needed to start this reaction, along with other difficulties, meant thorium was cast aside as a practical nuclear fuel, and instead uranium became the staple diet of reactors.

Today, it is just a by-product of rare earth mining. 3,200 tonnes of it are currently buried in the Nevada desert.

But countries are now waking up to the benefits of thorium, and it is once again being put to the test in Halden, a small Norwegian town with a population of less than 30,000. Thor Energy, with the help of Britain, the US and Germany, is testing thorium for commercial use. The company loaded its first fuel rods into a test reactor in April as part of a five year radiation programme designed to show the rest of the world what the company already knows: thorium is versatile, safe, and more efficient than uranium.

"The thermal conductivity of thorium based pellets is known to be much better to be much better than uranium, says chief executive Øystein Asphjell. "We are now proving that it is this way."

Mr Asphjell believes in what he calls an "evolutionary" approach to thorium - using the material in existing light water reactors to generate electricity.

Together with the UK's National Nuclear Labroratory, it is developing a variety of thorium fuel pellets, some designed to destroy old nuclear waste, others blending uranium and thorium to make a more stable fuel. "Thorium addresses a lot of the accident fallout from uranium because it has a much higher melting point, it cannot be dissolved in water, and there's multiple safety parameters that are inherant in the material properties," says Mr Asphjell.

Politicians are also listening. Michael Fallon, minister for business and enterprise, met with the All-Parliamentary group on Thorium Energy for the first time last month to discuss its benefits.

Kevin Hesketh, senior research fellow at the NNL, says that after years of neglect, the Government is now taking nuclear research more seriously, and believes that a thorium fuel cycle could be established in the UK within 20 years.

"We're discussing things with [the Government] routinely now. At one point we weren't getting any interest in nuclear research.

"They recognise that if you want to achieve an 80pc reduction in carbon emissions by 2050, it's going to require some pretty drastic changes."

Thorium "revolutionists" argue that the benefits could be even greater if it is used in molten salt reactors, which can act as eco-cleaners to burn up old toxic waste. Radioactive fission products can also be re-added to the reactor for successive rounds of power generation, making energy generation cheaper.

Some even argue that these reactors could have prevented the hydrogen explosions seen in Japan. In the event of power-loss, a plug in the base of the reactor melts and the salts flow into a containment vessel to cool down, stopping the reaction and any radiation release.

But in an industry where it costs billions - rather than millions - of pounds to conduct research, Mr Hesketh says Britain is likely to be a follower rather than a leader when it comes to thorium.

China launched a $350m (£223m) thorium-fuelled molten salt reactor Research and Development (R&D) programme in 2011, and plans to build commercially viable plants in the 2030s, while India, which has around 16pc of the world's thorium reserves, hopes to build four new fast breeder reactors by 2020.

Despite all the excitement, safety concerns mean nuclear developments continue to move at a glacial pace. Research takes years, if not decades, and the word "nuclear" still stirs up strong emotions. Earlier this month, politicians exchanged punches in Taiwan's parliament after a debate on the completion of its fourth nuclear power plant escalated.

But for countries such as Japan, an energy solution needs to be found, and quickly. Trade figures this week showed its reliance on LNG and petroleum post-Fukushima meant its trade deficit doubled to more than ¥1 trillion (£6.7bn) in July.

Takashi Kamei is president of Kyoto Neutronics, which is developing an accelerated neutron source to prepare thorium for use in a reactor.

"I think they have already reported my vision to Mr Abe," says Mr Kamei, though he recognises that the subject remains delicate in a country that is still reeling from the 2011 disaster. "If the prime minister says that Japan is developing molten salt reactors, and that this is quite safe – this implies that existing commercial plants are dangerous."

Mr Asphjell agrees. "This industry is so policy and public opinion driven that by saying we need to introduce thorium, you're by default saying there's something wrong with uranium.

"The existing industry does not want to get the message out there that there is something wrong with uranium. If you go 15 to 20 years back with the gasoline car industry versus electric cars - they didn't want to say that there was something better because they might break the market for the existing product."

Thorium's biggest enemy is often its own supporters, Mr Asphjell adds. "There have been a lot of loud voices in the UK that have taken a very evangelistic perpective on thorium - that it's a green fuel that solves every issue, it's employable tomorrow, there's no waste and absolutely no risk. This evangelistic view is diluting the proper message of thorium in many ways [and] from our perspective is the biggest obstacle for thorium introduction."

Mr Hesketh also sees the value in Britain doing more thorium research, but admits that only "market forces" will drive this forward. "Right now the support you need to get to the summit isn't there," he says."You haven't got the certainty of financial support to know that you're going to get to the summit, that would need to come at a later stage. But if you get yourself to base camp [by conducting research], you're in a much better position later."

For now, the world must look east for thorium developments, though Mr Asphjell is confident that slow and steady wins the race, despite the enormity of the task. "This is an elephant we're trying to eat," he insists. "We have to chew one piece at a time."